From 3dfd03fa89aa42d7d43bb00b2cd3f6d3428237ae Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Thu, 4 Jun 2026 22:12:29 +1000
Subject: [PATCH] [Bug] Fix for build forms (#12081)

* Bug fix for build forms

- Memoize outputs to prevent re-rendering reset issues

* Add playwright test
---
 src/frontend/src/forms/BuildForms.tsx      | 49 ++++++++++++++--------
 src/frontend/tests/pages/pui_build.spec.ts | 18 ++++++++
 2 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/src/frontend/src/forms/BuildForms.tsx b/src/frontend/src/forms/BuildForms.tsx
index c1ad970684..3fd3acbc41 100644
--- a/src/frontend/src/forms/BuildForms.tsx
+++ b/src/frontend/src/forms/BuildForms.tsx
@@ -343,16 +343,21 @@ export function useCompleteBuildOutputsForm({
     );
   }, [location, build.destination, build.part_detail]);
 
+  // Memoize the outputs once to avoid re-rendering issues
+  const buildOutputs = useMemo(() => {
+    return outputs.map((output: any) => {
+      return {
+        output: output.pk,
+        quantity: output.quantity
+      };
+    });
+  }, [outputs]);
+
   const buildOutputCompleteFields: ApiFormFieldSet = useMemo(() => {
     return {
       outputs: {
         field_type: 'table',
-        value: outputs.map((output: any) => {
-          return {
-            output: output.pk,
-            quantity: output.quantity
-          };
-        }),
+        value: buildOutputs,
         modelRenderer: (row: TableFieldRowProps) => {
           const record = outputs.find((output) => output.pk == row.item.output);
           return (
@@ -420,16 +425,21 @@ export function useScrapBuildOutputsForm({
     );
   }, [location, build.destination, build.part_detail]);
 
+  // Memoize the outputs once to avoid re-rendering issues
+  const buildOutputs = useMemo(() => {
+    return outputs.map((output: any) => {
+      return {
+        output: output.pk,
+        quantity: output.quantity
+      };
+    });
+  }, [outputs]);
+
   const buildOutputScrapFields: ApiFormFieldSet = useMemo(() => {
     return {
       outputs: {
         field_type: 'table',
-        value: outputs.map((output: any) => {
-          return {
-            output: output.pk,
-            quantity: output.quantity
-          };
-        }),
+        value: buildOutputs,
         modelRenderer: (row: TableFieldRowProps) => {
           const record = outputs.find((output) => output.pk == row.item.output);
           return (
@@ -486,15 +496,20 @@ export function useCancelBuildOutputsForm({
   outputs: any[];
   onFormSuccess: (response: any) => void;
 }) {
+  // Memoize the outputs once to avoid re-rendering issues
+  const buildOutputs = useMemo(() => {
+    return outputs.map((output: any) => {
+      return {
+        output: output.pk
+      };
+    });
+  }, [outputs]);
+
   const buildOutputCancelFields: ApiFormFieldSet = useMemo(() => {
     return {
       outputs: {
         field_type: 'table',
-        value: outputs.map((output: any) => {
-          return {
-            output: output.pk
-          };
-        }),
+        value: buildOutputs,
         modelRenderer: (row: TableFieldRowProps) => {
           const record = outputs.find((output) => output.pk == row.item.output);
           return (
diff --git a/src/frontend/tests/pages/pui_build.spec.ts b/src/frontend/tests/pages/pui_build.spec.ts
index 0979f7cf07..7243dd7994 100644
--- a/src/frontend/tests/pages/pui_build.spec.ts
+++ b/src/frontend/tests/pages/pui_build.spec.ts
@@ -379,6 +379,24 @@ test('Build Order - Build Outputs', async ({ browser }) => {
     )
     .waitFor();
   await page.getByRole('cell', { name: 'Quantity: 16' }).waitFor();
+
+  // Adjust the quantity field - we will only 'partially' scrap this output
+  await page.getByRole('textbox', { name: 'number-field-quantity' }).fill('10');
+
+  // Next, adjust the "location" field - and check that the "quantity" field does not change
+  // Ref: https://github.com/inventree/InvenTree/pull/12081
+  await page
+    .getByRole('combobox', { name: 'related-field-location' })
+    .fill('factory');
+  await page.getByTitle('Factory/Mechanical Lab').click();
+  await page.waitForTimeout(250);
+
+  // Check the 'quantity' value again - it should not have changed
+  const quantityValue = await page
+    .getByRole('textbox', { name: 'number-field-quantity' })
+    .inputValue();
+  expect(quantityValue).toBe('10');
+
   await page.getByRole('button', { name: 'Cancel', exact: true }).click();
 });